Emergency officials said that Hurricane Tomas, which has been battering east Caribbean islands with strong winds and rains, is moving on a westward track and might put Haiti at risk in the coming days.

The storm damaged homes, knocked out power and blocked roads with flooding and debris as it swept over St Lucia and St Vincent in the Windward Islands on Saturday.

"We have over 100 homes that have lost roofs. We expect that to increase," Michelle Forbes, the head of the National Emergency Management Organisation of St Vincent, said.

There were no reports of deaths, but Forbes told the Reuters news agency that two people were injured while trying to secure their roof.

More than 500 people have taken refuge in shelters, she said.

Earlier, Tomas damaged homes in Barbados, where some people took shelter in schools and churches.

Haiti fears

The storm was expected to gather strength, and officials say its impact on Haiti could be disastrous.

"This is a very dangerous hurricane that is just beginning to get going," Jeff Masters, a hurricane expert of private US forecaster Weather Underground, wrote in his blog.

"It's obviously the last thing Haiti needs."

Imogen Wall, UN spokeswoman in Haiti

"At this time, it appears that the Dominican Republic and Haiti are most at risk from a strike by Tomas, though the storm could move as far west as Jamaica, or as far east as the northern Lesser Antilles Islands."

Cholera has killed about 330 people in Haiti and infected more than 4,700 others.

The government and its international aid partners were discussing contingency measures for possible severe weather impact from hurricane Tomas.

Authorities are worried about the possible destructive effects powerful winds and torrential rain could have on the camps housing 1.3 million homeless survivors from Haiti's devastating January earthquake in the capital, Port-au-Prince.

"A hurricane is one of the things we've been preparing for ... but we're stretched to capacity handling the cholera epidemic," Imogen Wall, the United Nations humanitarian spokeswoman in Haiti, told Reuters.

"It's obviously the last thing Haiti needs," she said.

So far, only a few suspected cases have been reported in the capital.

At the La Piste camp, home to 50,000 Haitians, Red Cross workers were hurriedly putting up a medical observation centre to monitor and isolate suspected cases.

Posters were urging camp residents to maintain basic cleanliness, as poor hygiene contribute to the spread of the waterborne disease.

"Wash your hands with soap," one poster said.

"They are very simple messages, but they literally save lives," Samantha Georges, a British Red Cross spokeswoman, said.

"We have a truck that goes around with clowns on top, trying to engage people, trying to attract them."